CODEWITHSUNDEEP
pythonarraysnumpy
Martin Drech
Martin Drech

Reputation: 15

How can I concatenate arrays of arrays index by index?

If I have two or more n-dimenisonal arrays, each of which contains also arrays, how con I concatenate all of them index by index?

An example would be: 

A = np.array([[[1,2], [3,4]], [[4,5,6], [1]]])
B = np.array([[[10,20], [3,9]], [[7,5], [2]]])

and i would like to get 

C = np.array([[[1,2,10,20], [3,4,3,9]], [[4,5,6,7,5], [1,2]]])

Upvotes: 1

Views: 1508

Answers (1)

Eric
Eric

Reputation: 97641

Note that since your inner lists are of different lengths, you've ended up building 2×2 arrays of lists:

>>> A.shape
(2, 2)

But in numpy, + acts elementwise, and on lists, + does concatenation. So:

>>> C = A + B
>>> C
array([[[1, 2, 10, 20], [3, 4, 3, 9]],
       [[4, 5, 6, 7, 5], [1, 2]]], dtype=object)

Upvotes: 1

Related Questions